Preheat oven to 220 degrees celsuis fan-focred. Line an oven tray with baking paper. Place sweet potato on tray and drizzle with half of the oil. Bake for 15-20 minutes until tender. Mash in a bowl and set aside.

Coop lentils in a pan of boiling water for 15-20 minutes until softened. Drain well. Transfer to a large bowl to cool

Meanwhile, heat oil in a large frying pan on medium. Cook onion and garlic for 4-5 minutes until softened. Add spices and cook for 1 minute until fragrant. Add spinach, stirring until just wilted. Transfer to bowl with lentils and sweet potato.

Heat oil in frying pan on medium high. Cook patties for 2-3 minutes each side until golden. Drain on paper towel.